Power converter and methods of controlling the same

Patent metadata

Field	Value
Publication number	US-8942856-B2
Application number	US-201113334383-A
Country	US
Kind code	B2
Filing date	Dec 22, 2011
Priority date	Dec 22, 2011
Publication date	Jan 27, 2015
Grant date	Jan 27, 2015

Abstract

A power delivery system includes at least one conductor having a first end and a second end and a phasor measurement unit (PMU) coupled to the first end of the conductor. The PMU is configured to obtain phasor data at the first end and generate a phasor signal that includes the phasor data. The power delivery system also includes a power generation system coupled to the second end of the conductor and configured to provide power to the conductor. The power generation system includes a power source, a power converter, and a controller. The controller is communicatively coupled to the PMU and is configured to receive the phasor signal and control the power converter based at least partially on the phasor data.

First claim

What is claimed is:

1. A power delivery system comprising:
at least one conductor having a first end and a second end;
a phasor measurement unit (PMU) coupled to said first end of said at least one conductor, said PMU configured to obtain phasor data at said first end and generate a phasor signal that includes the phasor data; [[and]]
a power generation system coupled to said second end of said at least one conductor and configured to provide power to said at least one conductor, said power generation system comprising a power source, a power converter, and a controller, wherein said controller is communicatively coupled to said PMU and is configured to receive the phasor signal and control said power converter based at least partially on the phasor data;
a measurement device communicatively coupled to said controller and configured to:
measure at least one of a voltage and a current at said second end of said at least one conductor;
generate an output power signal that includes converter output data representing at least one of the voltage and the current measured at said second end of said at least one conductor;
wherein said controller is configured to:
determine an impedance (X) of said at least one conductor based on the converter output data and the phasor data; and
determine a maximum power an electrical grid is able to accept based at least partially on the impedance of said at least one conductor.

2. A power delivery system in accordance with claim 1 , wherein said at least one conductor comprises at least one transmission line configured to at least one of transmit and distribute power from said power generation system to the electrical grid.

3. A power delivery system in accordance with claim 1 , wherein said controller is configured to maintain phase synchronization between said power generation system and the electrical grid during a low voltage ride through event and/or a zero voltage ride through event by applying the phasor data to said controller operation.

4. A power delivery system in accordance with claim 1 , wherein said power source comprises at least one of a wind turbine generator and a photovoltaic array.

5. A power delivery system in accordance with claim 1 , wherein said controller comprises at least one of a central system controller and an individual converter controller.

6. A power delivery system in accordance with claim 1 , wherein said PMU comprises a global positioning system (GPS) receiver that receives a time reference signal used to time-stamp the phasor data.

7. A power delivery system in accordance with claim 6 , wherein the phasor data comprises at least one of a time-stamped current phasor and a time-stamped voltage phasor associated with power at said first end of said at least one conductor.

8. A power delivery system in accordance with claim 7 , wherein said controller comprises a GPS receiver that receives the time reference signal, said controller uses the time-stamped phasor data as at least one of a voltage reference and a current reference for controlling said power converter.

9. A power delivery system in accordance with claim 7 , wherein said controller controls said power converter to output power that is in phase with the power at said first end of said at least one conductor.

10. A power delivery system in accordance with claim 1 , wherein said controller controls said power converter to output power that is less than the maximum power the electrical grid is able to accept.

11. A method for controlling at least one power converter configured to provide power to an electrical grid through a transmission line, said method comprising:
monitoring a voltage output of the at least one power converter;
recording a voltage output data associated with the voltage output;
receiving a time reference signal and assigning a time-stamp to the voltage output data;
measuring a voltage phasor at a first location located at an opposite end of the transmission line from the at least one power converter;
receiving the time reference signal and associating the time reference signal with the voltage phasor to generate phasor data;
transmitting the phasor data to a power converter controller;
controlling, using the power converter controller, the at least one power converter based at least partially on the phasor data and the voltage output data;
determining a power output of the at least one power converter;
determining an impedance of the transmission line based at least partially on the power output and the phasor data; and
determining a maximum power the electrical grid is able to accept based at least partially on the impedance of the transmission line.

12. A method in accordance with claim 11 , further comprising synchronizing the voltage output of the at least one power converter with the phasor data.

13. A method in accordance with claim 12 , wherein synchronizing the voltage output of the at least one power converter with the phasor data comprises controlling the at least one power converter to output a voltage having a frequency that is in phase with the voltage measured at the first location.

14. A controller configured to control a power converter coupled to a transmission line having a first end and a second end, said controller comprising:
a global positioning device (GPS) receiver configured to receive a time reference signal;
a memory device configured to store voltage output data associated with a voltage output of the power converter, wherein the voltage output data includes voltage output data measured at the first end of the transmission line at a first time; and
a processing device configured to:
assign a time reference to the voltage output data stored in said memory device;
receive phasor data from a phasor measurement unit (PMU) positioned at the second end of the transmission line, wherein the phasor data includes a time reference tying the phasor data to the first time;
compare the phasor data from the first time to the voltage output data from the first time;
control operation of the power converter based at least partially on the phasor data and the voltage output data;
determine a power output of the power converter;
determine an impedance of the transmission line based at least partially on the power output of the power converter and the phasor data; and
determine a maximum power that said electrical grid is able to accept based at least partially on the impedance of the transmission line.

Assignees

• Ren Wei
• Delmerico Robert William
• O'Brien Kathleen Ann
• Pan Yan
• Gen Electric

Inventors

• Ren Wei
• Delmerico Robert William
• O'Brien Kathleen Ann
• Pan Yan

Classifications

• H02J3/18 Primary

  Arrangements for adjusting, eliminating or compensating reactive power in networks · CPC title

• Y02E40/30

  Reactive power compensation · CPC title

• H02J13/1323 Primary

  using optical fibres · CPC title

• H02J3/00144

  using phasor measuring units [PMU] · CPC title

• Y02E60/00

  Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation · CPC title